This relates generally to imaging systems and, more particularly, to imaging systems that use dark pixels to test the integrity of the imaging system.
Modern electronic devices such as cellular telephones, cameras, and computers often use digital image sensors. Imagers (i.e., image sensors) may be formed from a two-dimensional array of image sensing pixels. Each pixel receives incident photons (light) and converts the photons into electrical signals. Image sensors are sometimes designed to provide images to electronic devices using a Joint Photographic Experts Group (JPEG) format.
Over the lifetime of an electronic device, image sensors in the electronic device may be prone to failure. Conventional image sensors are sometimes provided with methods for testing the functionality of the image sensor when the electronic device is in stand-by mode. However, failure or error may occur during active operation of the electronic device or may otherwise be undetectable during stand-by mode.
It would therefore be desirable to provide improved imaging systems with capabilities to verify the functionality of the imaging system during active operation.